-2by3 raised to the power of 5
$${{\mathtt{\,-\,}}\left({\frac{{\mathtt{2}}}{{\mathtt{3}}}}\right)}^{{\mathtt{5}}} = {\mathtt{\,-\,}}{\frac{{\mathtt{32}}}{{\mathtt{243}}}} = -{\mathtt{0.131\: \!687\: \!242\: \!798\: \!353\: \!9}}$$
.